Governing mechanism for turbines.



0.JUNGGREN.

GOVERNING MECHANISM FOR TURBINES.

APPLICATION FILED AUG. 8, 1907- Patented Mar. 29; 1910.

4 SHEETS-SHEET l.

I /n ventor'z Oscar ULlJ Witnesses.-

ANDREW B. GRAHAM c0 FHOTO-LVTHOGRAFHERS WASMNBTOIL n c.

0. J UNGGREN. GOVERNING MECHANISM FOR TURBINES.

APPLICATION FILED AUG. 8, 1907.

Witnesses:

Ocardungren,

W mif 4 O.JUNGGREN.

I GOVERNING MECHANISM FOR TURBINES.

APPLIOATION FILED AUG. 8, 1907.

Patented Mar. 29, 1910.

' 4 SHEETS-SHEET 3.

M m ntor.- Oscardun Wit n esses new, $3

0.JUNGGREN.

GOVERNING MECHANISM FOR TURBINES.

APPLICATION FILED AUG. 8, 1907.

Patented Mar. 29, 1910.

4 SHEETS-SHEET 4.

/n vendor-.- 0605) Jun UNT'T OSCAR JUNGGREN, OF SCHENECTADY, NEW YORK,ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

GOVERNING MECHANISM FOR TURBINES.

To all whom it may concern:

Be it known that I, OSCAR JUNGGREN, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Governing Mechanism forTurbines, of which the following is a specification. V

The present invention relates to hydraulic governing mechanisms forelastic-fluid turbines.

It has for its object to improve and simplify their construction.

In the accompanying drawings, which illustrate one of the embodiments ofmy invention, Figure 1 is a partial View in elevation of a turbinegenerator; Fig. 2 is a plan view of the same; Fig. 3 is a detail view ofthe pilot-valve and the follow-up device for restoring it to the normalposition after responding to a change in speed; Fig. 4 is an axialsection of an oscillating motor for operating the cam shaft to open andclose the valves; Fig. 5 is a cross-section of the motor taken on theline 55 of Fig. 6; Fig. 6 is a partial plan view of the motor; Fig. 7 isa perspective View of the motor piston; Fig. 8 is a view in sideelevation of the bushing that contains the pilot valve; and Fig. 9 is asection through the pilot valve casing and exhaust pipe therefor.

1 indicates the casing of a turbine of the Curtis type, and 2 the stoolfor support-ing the generator 3. The generator is provided with a cover4 having a dome 5 the latter inclosing the speed-responsive device 6which may be of any suitable character, and is mounted upon the mainshaft 7, the latter being common to the rotating members of thegenerator and turbine. The governor is provided with weights 8 that movetoward or away from the axis of the shaft as the speed and load change.This motion is opposed by a spring inclosed by the barrel 9. Theresultant motion is conveyed to the governor lever 10. To the outer endof the lever is connected a rod 11 and this rod actuates the pilot valveof the motor, as will appear hereinafter. Steam is admitted to theturbine by one or more conduits 12 that communicate with the interior ofthe valve chest 18. In some instances one valve chest is suflicient andin other cases two chests will be provided. Mounted on the valve chestis a bracket 14 having bearings in Specification of Letters Patent.

Application filed August 8, 1907.

Patented Mar. 29, 1910.

Serial No. 387,600.

shaft are as many cams as there are valves, and as many valves areprovided as may be necessary to properly regulate the turbine underchanges in load. The position and relation of the cams on the shaft oneto the other will depend upon the direction of movement of the motorpiston in response to load changes. Each of these valves is actuated bya bifurcated lever 16 (Fig. 2) which is pivoted at its inner end to abracket or extension 17, and at its outer end is provided with a roller18 which rides on a cam directly underneath it. Each valve is providedwith an outside spring 19, Fig. 1, to close the same when the cam isrotated in a direction to lower the roller.

Mounted upon the same bracket 14 that carries the cam shaft is ahydraulic motor 20 of the oscillating type. By mounting the cylinder ofthe motor directly on the bracket and the piston axis concentric withthe cam shaft and directly connected thereto, the use of a large numberof parts is avoided and there is less danger from lack of alinement orsticking or binding, and since the number of parts is decreased therepairs will be less and the amount of attention required of the stationoperator will be reduced.

Referring more especially to Figs. 3 and a, 21 indicates the cylinder ofthe motor which is provided with heads 22 and 23. Mounted within thecylinder is a piston 2& comprising a central or hub portion 25 of steeland a rim portion 26 made of babbitt or other similar material. This isretained in place by screws 27 that are threaded into the hub 25, thebabbitt being cast around the screws and afterward finished to thedesired dimensions. By making the hub of a separate piece it can beaccurately turned to the desired dimension and will be absolutely roundand therefore make a good surface to which the stationary abutment inthe cylinder may be fitted. By making the piston proper of babbitt itcan be taken out and peened to compensate for any slight wear that maytake place. The right-hand head 23 is perforated centrally to receivethe projecting end of the hub 25 and is beveled at 28 to receive acorrespondingly beveled shoulder on the hub. The head 22 is unperforatedbut is provided with a recess 29 to receive the left-hand end of the huband which is located a cam shaft 15. On this i form a bearing therefor.Between the head 22, which serves as an abutment, and the hub is acoiled compression spring 30 which serves at all times to press the hubto the right and maintain a tight fit between the conical surface 28 andthe cooperating shoulder on the hub. By reason of this construction I amable to dispense with the usual packing glands employed for maintainingtight joints between moving and stationary parts, and by making the head22 in one piece I avoid the use of a shaft packing at this point.

In any structure of this kind it is desirable to separate the drivingfrom the driven parts with a minimum expenditure of labor. It is alsodesirable to have some form of connection between the two parts whichwill compensate for any lack of alinement due to expansion andcontraction or to inaccuracy in machine work. To this end the righthandend of the hub 25 is slotted, as best shown at 31, Fig. 7. Secured inthis slot is a key 32, Fig. 4, which engages a corresponding slot in theprojecting end of the cam shaft 15. The key 32, in addition to unitingthe parts and causing corresponding angular movement of the same, actsas a part of the stop for limiting the angular movement of the motorpiston thereby preventing injury to the piston. In one position the pin33 acts as a stop, and in the other position the pin 34.

The admission of fluid to the motor is controlled by a pilot valvelocated in the casing 35, the latter being formed integral with the head23, or it may be bolted thereto, as desired. Located inside of thecasing or cylinder is a bushing 36 having ports 37 and 38 leading toopposite sides of the stationary abutment 39 in the motor cylinder, andhighpressure ports 40 which are always in communication with theadmission pipe 41. The admission pipe may be connected with any suitablesource of liquid pressure; in

the present instance it is intended to be connected with the same sourceof supply that lubricates the step-bearing of the turbogenerator. Thepassage 42 conveys fluid from the port 37 to the under side of theradial abutment 39, as best shown in Fig. 5, while the passage 43conveys liquid from the port 38 to the upper side of the abut-- ment 39.Located within the bushing 36 is a balanced piston valve 44 the stem ofwhich is extended upward through a guide at the top of the valve casingand is connected to the lever 45, one end of which is pivotally unitedwith the governor lever 10 through rod 11. As the piston valve is movedup or down it admits fluid to the various ports and cuts off the same asoccasion demands.

Extending longitudinally of the bushing 36 and between it and the casingare vertical chambers or passages 56 as shown in Figs. 3 and. 9. It willbe noted that the bushing is shorter than its inclosing casing, Fig. 3,and hence said chambers or passages are connected at the top and bottom.Both of these chambers exhaust into the discharge pipe 57 as shown inFig. 9.

In a system of this kind employing high pressure I have found that thereis a tendency for the pilot valve to stick under certain conditions. Forexample, assume that the load is substantially constant for anappreciable interval of time. There is always high pressure between theheads of the pilot valve, while above and below the heads the pressureis that of the exhaust. In the present instance it is atmosphericpressure. There is of course a tendency for the liquid to flow past theheads and escape into the region of low pressure beyond. The fit is madeas close as possible between the piston heads and the sleeve, but it isnecessary to have a certain freedom of movement at this point, and theparts are also subjected to a slight amount of wear. As the fluid tendsto flow from the high-pressure point to the region of low pressure, itforces the pistonhead to one side of the cylindrical bore of thebushing, thus enlarging the space on one side and shutting it off on theother. This brings the metal of the bushing and the heads into directcontact, hence it is nec essary for the governor to overcome this beforeit can move the valve. To overcome the objection noted I turn grooves inthe pistons and leave narrow flanges 46 to reduce the effective sidethrust. In other words the side thrust is now due to the area of theflanges and not to the area of the whole piston.

In a construction of this kind it is necessary to provide means forpreventing the governor from ovcrtraveling. To this end I mount on thecam shaft 15 a pinion 47 which has the same angular movement as themotor piston. The pinion meshes with a vertically extending rack 48, therack being held in mesh by a roller 49 engaging the back thereof. Theupper end of the rack is connected to the lever 45 which is actuated bythe governor. Assuming, for example, that the governor raises the rod11, and with it the lever 45 about the pivot 50 and the pilot valve, theport 37, which is normally closed, will be open to high pressure, andthe port 38, which is also normally closed, will be open to lowpressure. As a result, the high-pressure fluid will flow through thepassage 42 to the under side of the abutment 39 and move the piston 24in a clockwise direction, it being assumed of course that the parts werein an intermediate posi tion at starting. Just as soen as the pistonbegins its movement the pinion 47 will begin to move the rack 48downward and in so doing move the lever 45 about the pin 50 as' afulcrum and with it the pilot valve until the ports 37 and 38 areclosed, When the motor will stop. In this manner the action of the motorin a sense anticipates the movement of the governor and stops the motorfrom operating before the governor feels the effects of the change inspeed. The same action takes place when the rod 11 is pushed down by thegovernor lever except that the parts move in the opposite direction.

l/Vhere the machine to be governed is of large capacity, it ispreferable to admit steam or other motive fluid at two points onopposite sides of the wheel, as shown in Fig. 2 to equalize thedischarge of steam to the bucket wheel or wheels. The valve-actuatingmechanism of both steam chests is the same, but only one motor isnecessary for operating the parts. In order that a single motor may moveboth of the cam shafts simultaneously, a pinion 51, Figs. 1 and 4, ismounted on the cam shaft 15, which meshes with a horizontal rack 52 thatis guided on its upper side by a roller 53. The rack extends across themachine from side to side, and meshes with a pinion mounted on thecam-shaft 54, Fig. 2, which pinion is in all respects like the pinion 51on the shaft 15. The rack is held in engagement with the pinion on theshaft 54 by the combined guide and roller By reason of this constructionit follows that whenever the camshaft 15 is moved, the cam-shaft 54 ismoved by a corresponding amount, and in the same direction.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative, and that the invention can be carried out by other means.

hat I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. In a governing mechanism for turbines, the combination of a pluralityof valves, an oscillating cam shaft for actuating the valves, a motorcomprising a stationary member and an oscillating member, the latterbeing directly connected to the cam shaft and having the same angularmovement, a regulating valve for the motor, and a governor responsive toload changes for moving the regulating valve.

2. In a. governing mechanism for turbines, the combination of aplurality of valves, an oscillating cam shaft for actuating the valves,a motor, the movable member of which is directly connected to the camshaft and has the same angular movement, a regulating valve for themotor, a governor re-' sponsive to load changes for moving the valve,and a device moving with the cam shaft for restoring the regulatingvalve to its normal position to prevent overtravel.

3. In a governing mechanism for turbines, the combination of a pluralityof valves, a cam shaft for actuating the valves, a motor the movablemember of which is directly connected to the cam shaft and has the sameangular movement, a regulating valve for the motor, a governorresponsive to load changes for moving the valve, a pinion driven by themotor, and a rack which is moved by the pinion and restores theregulating valve to prevent overtravel of the motor.

4. In a governing mechanism, the combination of a plurality of valves, acam shaft for actuating them successively both in opening and closing,an oscillating fluid-actuated motor the movable member of which is inaxial alinement with the cam shaft, a means uniting the member and theshaft so that their angular movements are equal, and a governor-actuatedmeans for controlling the motor.

5. In a governing mechanism, the combination of a plurality of valves, acam shaft for actuating them successively both in opening and closing,an oscillating fluid-actuated motor the movable member of which-is inaxial alinement with the cam shaft, a means uniting the member and theshaft so that their angular movements are equal and in the samedirection, stops which limit the angular movements of said member inboth directions from a given neutral point, and a governor-actuatedmeans for controlling the motor.

6. In a governing mechanism, the combination of a plurality of valves,means for actuating them, a hydraulic motor for driving said means whichcomprises a cylinder, a radial abutment, a piston the spindle of whichis seated fluid-tight in one of the cylinder heads, a regulating valvefor the motor, a speed governor for actuating the valve, and a restoringdevice for the valve to prevent angular over-travel of the motor piston.

7. In a governing mechanism, the combination of a chest, valves therein,a cam shaft for actuating the valves successively, a bracket whichsupports the cam shaft, an oscillating fluid-actuated motor which iscarried by the bracket, a connector for uniting the movable element ofthe motor and the cam shaft and causing corresponding angular movements,and a governor-controlled valve for regulating the motor.

8. In a governing mechanism, the combination of a valve, a cam and shaftfor actuating it, an oscillating motor, mounted in axial alinement withthe shaft, a coupling uniting the movable member of the motor with thecam shaft which permits of slight independent axial movements of themotor and cam shaft but looks them against independent angularmovements, a regulator for the motor, and a governor controlling theregulator.

9. In a governing mechanism, the combination of chests arranged atseparated points on the machine being governed, valves in each chest, acam shaft for actuating each set of valves, pinions on the shafts, arack connecting the pinions for insuring corresponding angular movementsof the shafts, an oscillating motor concentrically arranged With respectto one of the cam shafts, a means uniting the movable member of themotor With the said shaft, and causing corresponding angular movementsthereof, a follow-up device for preventing excessive angular movement ofthe movable member of the motor and the cam shafts, and a governor forcontrolling the motor.

10. In a governing mechanism, the combination of a plurality of valves,a lever for operating each of the valves, a cam shaft for moving thelevers, an oscillating hydraulic motor comprising a piston and cylinder,the piston being in axial alinement With the cam shaft, a regulatingvalve, a restoring device for the valve, and a governor for actuatingsaid valve.

11. In a governing mechanism, the combination of a valve, a motor foractuating it comprising a cylinder and an oscillating piston composed ofa cylindrical hub having projections thereon and a soft metal portionattached thereto and partially held by said projections, a regulatingvalve for the motor, and a governor controlling the action of theregulating valve.

In Witness Whereof, I have hereunto set my hand this 6th day of August,1907.

OSCAR J UNGGREN.

Witnesses:

BENJAMIN B. HULL, HELEN Onronn.

